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==Risk factors==
 
==Risk factors==
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Studies have shown that dogs with a reduced thoracic width to depth ratio are at a in increased risk of developing GDV. Other risk factors include obesity, stress,exercise following feeding and feeding of a dry food diet. Female dogs are also more likely to develop GDV than males.  
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Studies have shown that dogs with a reduced thoracic width to depth ratio are at a in increased risk of developing GDV. Other risk factors include obesity, stress, exercise following feeding and feeding of a dry food diet. Female dogs are also more likely to develop GDV than males.
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==Pathogenesis==
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GDV ssually occurs around 30 minutes after a meal, or following aerophagia. The stomach becomes distended (gastric dilation). The animal excercises, and the stomach twists 180 degrees clockwise on its mesentery. Torsion impairs the blood supply- the arterial supply is maintained but venous drainage is blocked. The gastric wall becomes severely congested and infarction of gastric mucosa may occur. The stomach becomes distended with gas and fluid, causing blocked venous return to heart. This compresses the diaphragm and interferes with respiration.
    
==History and Clinical signs==
 
==History and Clinical signs==
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==Diagnosis==  
 
==Diagnosis==  
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Diagnosis is usually based on the patient's history of unproductive vomiting and abdominal distension and signalment (i.e. a large breed dog). Abdominal radiography may be beneficial in confirming a diagnosis of GDV and distinguishing between GDV and gastric dilatation. Radiography should not be carried out until gastric decompression has been performed and intravenous fluids have been started. A radiograph performed in right lateral recumbency shows a dorsally and cranially positioned pylorus to the left of the midline. The stomach will appear compartmentalised with a soft tissue strip separating the two compartments. The oesophagus may appear dilated with air or fluid. Evidence of air in the abdomen indicates that perforation has occurred and requires an exploratory surgical procedure.  
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Diagnosis is usually based on the patient's history of unproductive vomiting and abdominal distension and signalment (i.e. a large breed dog). Abdominal radiography may be beneficial in confirming a diagnosis of GDV and distinguishing between GDV and gastric dilatation. Radiography should not be carried out until gastric decompression has been performed and intravenous fluids have been started. A radiograph performed in right lateral recumbency shows a dorsally and cranially positioned pylorus to the left of the midline. The stomach will appear compartmentalised with a soft tissue strip separating the two compartments. The oesophagus may appear dilated with air or fluid. Evidence of air in the abdomen indicates that perforation has occurred and requires an exploratory surgical procedure. Loss of contrast in the abdomen may indicate peritonitis or haemoabdomen.
 
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(GDV x-ray from WikiCommons[[http://commons.wikimedia.org/wiki/File:GDV_x-ray.JPG]])
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The contrast of the abdomen may be lost indicating peritonitis or [[Haemoabdomen|haemoabdomen]]. Gastric rupture would show as pneumoperitoneum and increased contrast.
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===Haematology===
 
===Haematology===
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===Biochemistry===
 
===Biochemistry===
 
Most commonly find hypokalaemia and metabolic acidosis. The acidosis is caused hypoperfusion and anaerobic metabolism leading to lactic acid accumulation. Respiratory acidosis and alkalosis may also be present due to hypo- and hyperventilation.
 
Most commonly find hypokalaemia and metabolic acidosis. The acidosis is caused hypoperfusion and anaerobic metabolism leading to lactic acid accumulation. Respiratory acidosis and alkalosis may also be present due to hypo- and hyperventilation.
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==Treatment==
 
==Treatment==
The most important first line treatments are [[Principles of Fluid Therapy|fluid therapy]] and gastric decompression.
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The most important first line treatments are fluid therapy and gastric decompression. Large bore (16 or 18 gauge) catheters should be placed into the cephalic or jugular veins (ideally two into both cephalic veins). Shock doses of Compound Sodium Lactate (Lactated Ringer's Solution) (60-90ml/kg/h) should be administered. Monitoring of the animal's cardiovascular status  should be done by regular blood pressure measurements, heart rates, PCV and total solids and urine output.
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===Fluid therapy===
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Gastric decompression is performed by introduction of a lubricated premeasured (from nostril to last rib) stomach tube or by trocharizing the most tympanic area caudal to the ribs with a 14 to 16 gauge catheter. Sedation may be required to allow the passage of the stomach tube. Suitable drugs for this include Butorphanol, Fentanyl or diazepam.
Should be individualised to the patient due to the varying nature of the [[Essential Ion and Compound Balance and Homeostasis - Anatomy & Physiology#Acid / Base|acid-base]] disturbances. Large bore (16 or 18 gauge) catheters should be placed into cephalic or jugular veins (ideally two into both cephalic veins). Shock doses of Compound Sodium Lactate (Lactated Ringer's Solution) (60-90ml/kg/h). Hypertonic saline can also be used. Monitoring of the situation should be done by regular blood pressure measurements, heart rates, PCV and total solids and urine output. Potassium can be supplemented to bags in the form of KCl after the initial shock doses.
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===Gastric decompression===
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Other treatment may include broad spectrum antibiotics e.g. Cephalosporin and a Fluoroquinolone. Thses should also be given at surgical induction through to the postoperative period. For cardiac arrythmias: indicated if weakness, syncope, tachycardia runs with R on T complexes, ventricular tachycardia at rates >150bpm. Treated by correcting [[Essential Ion and Compound Balance and Homeostasis - Anatomy & Physiology#Acid / Base|acid-base]], [[Essential Ion and Compound Balance and Homeostasis - Anatomy & Physiology|electrolyte]] and [[Haemostasis - Pathology|haemostatic]] disturbances. The treatment is [[Local Anaesthetics#Lidocaine|lidocaine]] by bolus or continuous rate infusion or procainamide if they persist.
Performed by introduction of a lubricated premeasured (from nostril to last rib) stomach tube or by trocharizing the most tympanic area caudal to the ribs with a 14 to 16 gauge catheter. Sedation may be required to allow the passage of the stomach tube. Suitable drugs for this include [[Opioids#Butorphanol|butorphanol]], [[Opioids#Fentanyl|fentanyl]] or oxymorphone and [[Benzodiazepines#Diazepam|diazepam]].
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===Other treatment===
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*For shock: [[Steroids|Prednisolone sodium succinate]] or [[Steroids|dexamethasone sodium phosphate]].
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*For bacterial translocation and endotoxaemia: Broad spectrum antibiotics (e.g. [[Cephalosporins|cephalosporin]] and a [[Fluoroquinolones|fluoroquinolone]]) should also be given at surgical induction through to the postoperative period.
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*For cardiac arrythmias: indicated if weakness, syncope, tachycardia runs with R on T complexes, ventricular tachycardia at rates >150bpm. Treated by correcting [[Essential Ion and Compound Balance and Homeostasis - Anatomy & Physiology#Acid / Base|acid-base]], [[Essential Ion and Compound Balance and Homeostasis - Anatomy & Physiology|electrolyte]] and [[Haemostasis - Pathology|haemostatic]] disturbances. The treatment is [[Local Anaesthetics#Lidocaine|lidocaine]] by bolus or continuous rate infusion or procainamide if they persist.
   
*For analgesia: Pure [[Opioids|opioid]] of [[Opioids#Morphine|morphine]], [[Opioids#Methadone|methadone]] or [[Opioids#Fentanyl|fentanyl]].
 
*For analgesia: Pure [[Opioids|opioid]] of [[Opioids#Morphine|morphine]], [[Opioids#Methadone|methadone]] or [[Opioids#Fentanyl|fentanyl]].
 
*General: Oxygen supplementation if possible
 
*General: Oxygen supplementation if possible
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* Animal collapses suddenly and must be operated on rapidly.
 
* Animal collapses suddenly and must be operated on rapidly.
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===Pathogenesis===
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* Usually occurs around 30 minutes after a meal, or following aerophagia.
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** [[Forestomach - Anatomy & Physiology|Stomach]] is distended (gastric dilation).
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** Animal excercises, and the [[Forestomach - Anatomy & Physiology|stomach]] twists 180 degrees clockwise on its mesentery.
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* Torsion impairs the blood supply- the arterial supply is maintained BUT venous drainage is blocked.
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** [[Forestomach - Anatomy & Physiology|Stomach]] wall becomes severely congested and infarction of gastric mucosa may occur.
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* [[Forestomach - Anatomy & Physiology|Stomach]] blows up with gas and fluid.
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** Block venous return to heart.
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** Compresses diaphragm and interferes with respiration.
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* '''The actual cause of the problem and the reason for accumulation of gas is unclear.'''
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** It is better to feed big dogs small amounts more frequently.
      
===Pathology===
 
===Pathology===
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** Becomes very congested and moves from left to right side of abdomen.
 
** Becomes very congested and moves from left to right side of abdomen.
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====Histological====
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[[Category:Stomach_and_Abomasum_-_Pathology]][[Category:Dog]]
 
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* Venous obstruction gives rise to congestion, oedema and necrosis of gastric mucosa.[[Category:Stomach_and_Abomasum_-_Pathology]][[Category:Dog]]
   
[[Category:To_Do_-_SophieIgnarski]]
 
[[Category:To_Do_-_SophieIgnarski]]
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